Method for producing composite titanic-oxid products.



LOUIS n. BARTON, or NIAGARA FALLS, NEW YORK, AssIerNonTo TH-n TITANIUMALLOY MANUFACTURING COMPANY, on NEW YORK, N. Y., A CORPORATION OFMAI-NE.

METHOD FOR PRODUCING COMPOSITE TITANIC-oxIi) isomers.

No Drawing.

To all whom it may concern Be it known that I, LOUIs E. BARTON, acitizen of the United States, and a resident of Niagara Falls, in thecounty of Niagara and State of New York, have invented certain new anduseful Improvements in Methods for Producing Composite Titanic- OxidProducts, of which the following is a specification.

My present invention relates especially to such products utilized aspigments in paint, including others also, containing importantpercentages of titanic oxid. Its objects comprise provision of methodswhereby, as is desirable for certain purposes, composite titanic oxi'dpigments can be, on industrial scales of manufacture, produced by aid ofprecipitation of orthotitanic acid on suspended particles of any desiredsubstance, thus including even extender pigments of the types familiarin the paint art, there being thus imparted to the resulting proclucts,or pigments, qualities rendering them exceptionally useful for certainpurposes.

In Letters Patent No. 1,155,462, dated October 5th, 1915, Ihavedisclosed and claimed a process for producing compound titanic oxidproducts, or pigments, by aid of pre cipitation of metatitanic acid uponparticles of a suspended base, the precipitation in those instancesoccurring by aid of addition of salts hydrochloric acid solutions.

In my pending application for patent Serial Number 861,184, filedSeptember 11, 1914i, I have disclosed a process, invented by me, forobtaining pure titanic oxid by aid of precipitating metatitanic acidfrom hydrochloric acid solutions and calcining the precipitate, thefinal product being a soft fine powder suitable for pigment purposes.

I am aware that by addition to a titanic solution of a base, such asammonia, or soda, to neutrality of the solution, orthotitanic acid isprecipitatable, but this acid thus precipitated is, when separated,dried and calcined, usually of too coarse, and gritty con- Specificationof Letters Patent.

Patented July '24, 191?.

sistency and texture to be well suited for pigment purposes, although ifground to a fine powder it may, "when mixed with oil, possessconsiderable of the hiding power which is "essential in paint.

My present invention comprises the discovery that if orthoti'tanic aci'dbe precipitated in any titanicsolution 'containing suit able suspendedparticles of a substance, or substances, (hereinafter referred to "assuspended base pigments), upon which the orthotitanic acid can, ihgelatinou's state, fix itself, or with which it can coalesce, and thecomposite results of such precipitation and coalescence be then filteredout and calcined, the final product's, instead of being coarse andgritty, will prove to be extremely fine, soft, smooth, powders andcorrespondingly superior for such purposes as pigments.

My invent-ion comprises also the discovery that suspended bases suitablefor such reception of, and coalescence with, the thus precipitatedorthoti'tanic acid, include the so called extender pigments used in compounding paints, such, for example, as barytes (natural barium sulfate),silica, china-clay, asb'estin, etc.

I have discovered that a suitable precipitating agent when such extenderpigments are thus employed be any of the alkalis as, for example, sodiumhydroxid, ammonium hydroxid, potassium carbonate, or sodium su'lfid.

And a particularly important feature of my invention is my furtherdiscovery that the best final products are obtainable, and with greatereconomy, by operating in a titanic sulfate solution, treated with areagent which is capable both of acting as the precipitant of theOrtho'titanic acid, and also of supplying by reaction with the solutionthe required suspended base particles. My researches have demonstratedthat the alkali earth bases can be successfully used as such lastreferred to reagent, viz: calcium hydrate, CaKOHM '01 barium hydrate,

insoluble in Water.

Ba(OH) or barium sulfid, BaS, or other bases the sulfates of which arepractically obtained arefine, soft, powders consisting Y of amorphous,titanic oxid, coalesced with a sulfate base.

In the various applicat ons of my 1nvention, the chemical compositionand specific gravity of the final products will, of course, depend uponthe nature of the precipitating agent employed and the composition ofthe titanic solution used.

The color of my products will, of course, dependalpon the purity of thematerials; thus, for example, if the titanic sulfate solution employedis practically free from iron, the product will be ,white, and willrange from this to light, or even dark, cream copper, or other elements,whosesulfids are sulfates tobe acted upon. When several precolor,in-proportion to iron present.

, I provide procedures whereby my highest grade product may be derivedfrom rela-' tively impure titanic solutions, as for example, thosecontaining small quantities of insoluble in dilute acids. Suchimpurities I remove by passing hydrogen sulfid gas into the. solutionand filtering out the preciptated Should the titanic solution contain,as an impurity, more iron than desired, I use as the precipitating agenta sulfid, or a mixture of a sulfid with an oxid base. In eithe'rcase.

the iron'will be precipitated with the prodnot as iron sulfid. Forexample, if it is desired-to precipitate the orthotitanic acid on asilica suspended base which has been added as such to the solution,.Iadd as the precipitating agent sodium sulfid, or a mixture of sodiumhydroxid, or of sodium carbonate, with sodium sulfid. If, on theotherhand, the suspended base is, as above described, formed byprecipitation of sulfates in a titanic sulfate solution, I addto-thelatter purified from copper and other impurities as abovedescribed,.barium sulfid as the'precipitant, or a mixture of calciumhydrate and sodium sulfid, or a mixture of calciumhydrate and bariumsulfid, the essential being to add enough of the sulfid to insure thepre-' cipitation of the iron in the form of iron sulfid. It is myexperience that in such cases the precipitant substances employedshould, for the best results, contain of the sulfid the chemicalequivalent of atleast 25% of the cipitants are thus employed together itis usually preferable, though not invariably necessary, that they bemixed before addition, but in some casesit is better to add themsuccessively. For example, if one of the precipitants is calciumhydrate, by first adding it separately, opportunity is afforded for itscomplete reaction with sulfates in. solution, thus insuring presence ofthe resulting suspended base, required, before ad dition of the morequickly reactive sulfid.

The pigment product having thus been precipitated, I conduct sulfurdioxid gas into the solution until the iron sulfid is decom .posed anddissolved. Though this may result in the solution being then slightlyacid 30 with sulfurous acid, the latter does not react to dissolvetitanic acid or precipitated base more than negligibly, and thereforedoes not substantially impair yield of the, final product.

I first obtain, or prepare, in any convenient manner, a titanicsolution, the which may be either a hydrochloric, asulfuric, or other,acid, solution, except that, if the suspended base is to be formed byits precipitation therein, a titanic sulfate solution is preferable, andI will, therefore, assume such to be the one employed in what fol lows.To such solution I either add the de sired extender pigment as such, orthe precipitant or precipitants, referred to, the latter beingpreferably dissolved, or at least suspended, in water; or, in somecases, I may addboth the extender and the precipitant to the titanicsolution.

From analysis of the latter I calculate the quantity'of precipitant, ormixture of precipitants, required, the rule being that, in practicallyall cases, such quantity be sufiicicnt to combine with all the sulfatein the solution except sodium sulfate. Slight discrepancies between whatcalculated and required may be compensated by adding the precipitantslowly and stopping when the mixed solution shows a slightly alkaline noreaction; v

During the precipitation I thoroughly agitate the solution, and thisparticularly if an extender pigment has been incorporated and suspendedas aforesaid to form the suspended base pigment. After the precipitationthe solution is ready for the next step in my process, though if a partof theprecipitant has been added in undissolved, i. 0. alreadysuspended, form, as

would be calcium hydrate for example, it is better practice to allow thecharge to stand with occasional agitation during an interval of say onehalf an hour to an hour in order to insure more complete reactionbetween the precipitant and the sulfates in solution.

In operations in which I desire that the precipitated product shall bepurified r m iron in the solution, I, at this stage, incorporatesulfurous acid as by conducting sulfur dioXid gas into the charge asbefore described, thus decomposing and dissolving the iron sulfidpresent.

My next step in the operation is to filter out the precipitate, which Ithereafter wash with cold water, dry, and calcine at a temperature offrom say 600 C. to 800 (1., thus obtaining my final composite titanicoXid product, or pigment.

In my herewith copending application for Letters Patent Serial Number23,520, filed April 23, 1915, I have described and claimed a method, andresulting product, whereby, by aid of alkali earth bases added asprecipitants to a titanic sulfate solution, there are thereinprecipitated sulfate particles, and also particles of basic titanicsulfate (i. e. titanic sulfate combined with hydrated titanic oxid), theresulting uncalcined composite precipitate product being distinguishedas consisting essentially of such sulfate particles coalesced with saidbasic titanic sulfate.

ployed in my previous method is insufficient to produce a permanentprecipitate of orthotitanic acid, also in that requisite acidity of thetitanic solution is, in my previous method, insured by additions ofsulfuric acid, and the charge is heated and otherwise treated so as toinsure that its titanic constituents shall precipitate in the form ofbasic titanic sulfate, while, by my present Y method, the procedure isaltered so as to in sure precipitation of orthotitanic acid, and,consequently, the quantity of the alkali earth bases is not sorestricted. Titanic acid solutions other than titanic sulfate may, incertain cases, be employed as above stated. Additions of acid areomitted and the charge is not heated.

Each of my said methods possesses its own characteristic and distinctiveadvantages in procedure and results, and, as regards special uses forits respective prod ucts.

The uncalcined composite precipitate prod uct of my present method is ofdistinctive and special utility for certain purposes in the arts, and,when dried, it consists essentially of particles of extender pigment, orof sulfate particles, or of both, having therewith coalesced very minuteparticles of orthotitanic acid.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is the following, viz

l. The method of treating a titanic sulfate solution which comprisesprecipitating therein sulfate particles, and also particles oforthotitanic acid.

2. In the production of composite titanic products from a titanicsulfate solution, the step which consists in adding to such solution areagent capable of acting therein both as a precipitant of sulfateparticles, and also of orthotitanic acid particles, and thereaftermaintaining the charge so as to insure precipitation of titanicconstituents in the form of orthotitanic acid.

3. The method of producing composite titanic oXid pigments whichcomprises adding to a titanic sulfate solution a base capable of thereinforming an insoluble sulfate, and thereafter maintaining the charge soas to promote precipitation therein of orthotitanic acid.

4. In the production of composite titanic oXid products from a titanicsulfate solution, the step which consists in adding to such solution analkali earth base.

5. In the production of composite titanic oXid products from a titanicsulfate solu tion, the step which consists in adding to such solutioncalcium hydrate.

6. In the production of composite titanic oXid products from a titanicsulfate solution, the step which consists in adding to such solution areagent capable both of acting as a precipitant of orthotitanic acid,and also of supplying to the solution by reaction therewith suspendedbase pigment particles.

7. The method of producing pigments containing titanic oXid from atitanic sulfate solution, which comprises adding to such solution areagent capable both of act ing as a precipitant of orthotitanic acidand also of supplying to the solution by reaction therewith suspendedbase pigment particles, withdrawing the resulting orthotitanic acidprecipitate together with said particles, and calcining them.

8. The method of producing pigments containing titanic oXid from atitanic sulfate solution which consists in adding thereto an alkaliearth base, withdrawing therefrom the resulting composition oforthotitanic acid precipitate and therewith coalesced sulfate basepigment, and calcining it.

9. The method of producing pigments containing titanic oXid from impuretitanic sulfate solutions which comprises passing hydrogen sulfid gasinto the solution, filtering out precipitated sulfids, adding to thefiltrate an alkali earth base, withdrawing therefrom the resultingcomposition of orthotitanic acid precipitate and therewith it coalescedsulfate base pigment, and calcining it. 7

10. The method of reducing pigments containing titanic oxid romiron-containing 5 titanic sulfatesolution which comprises adding to suchsoiution anv alkali earth sulfid base, adding sulfurous acid to thecharge, withdrawing therefrom the resulting. composition oforthotitanicacid precipitate and 10 therewith coalesced sulfate base pigment,

- and calcining such composition. V

11. In the production of composite titanic products from atitanicsolution,"'the" step Louis E. BARTON.

Witnesses:

WM. V. KNOWLES, C. J; Kmzm.

V copies oi this patentmay-be obtained for five 'cents each, byaddressing the (Commissioner of fatents. Washington, I). 0.

